JP2003308534A - White line recognizer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To appropriately determine a line delimiting the position and shape of a side edge portion of a lane. <P>SOLUTION: A white line recognition part 2 for determining a white line position from a road surface image ahead of a vehicle photographed by an imaging part 1 scans the road surface image laterally in each longitudinal position of the road surface image to detect an edge pair comprising an up edge with increasing lightness and a down edge with decreasing lightness and extract a bright portion by a white line, and if observing an arrangement of a plurality of edge pairs, sets a white line position candidate point in a point positioned relative to the plurality of edge pairs according to the arrangement. Even in a road portion with an arrangement of a plurality of white lines, a white line position candidate point that would be determined if the road portion were a road portion with a single white line can be determined. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a white line recognition device for recognizing a white line from a road surface image in front of a vehicle.

[0002]

2. Description of the Related Art A white line is drawn on the road surface to clarify the side edge of the lane, which is the most basic information for grasping the traveling position of the own vehicle. In recent years, a technique has been proposed in which a white line is used as a guide sign when a vehicle is allowed to travel by automatic steering. In this technology, a white line recognition device mounted on a vehicle captures a road surface image in front of the vehicle by an image pickup means such as a CCD camera, and utilizes the fact that the brightness is high at the position of the white line to extract the bright part of the white line to extract the white line. To recognize. In such a system, Japanese Patent Laid-Open No. 7-228268 discloses an up edge in which a road surface image is horizontally scanned at each position in the vertical direction, and the brightness of a pixel changes relatively higher than a predetermined level.
The white line position representing the side edge of the lane is detected based on the paired edge consisting of the up edge and the down edge by detecting the down edge in which the brightness of the pixel changes relatively lower than a predetermined value and extracting the bright part. Candidate points have been decided.

Huff transformation and filtering are performed based on the group of white line position candidate points to estimate a line describing the position and shape of the side edge of the lane on which the own vehicle is traveling. In the Hough transform, a frequently-occurring parameter is obtained as a plurality of parameters that specify a line (for example, a straight line) that passes through each white line position candidate point in the road surface image, and the line specified by the frequently-occurring parameter is used as the basis of estimation. I am trying.

In the calculation of the position and shape of the side edge of the lane, in order to improve accuracy and responsiveness, it is necessary that the white line position candidate points are found to some extent correctly. According to the technique disclosed in Japanese Patent Laid-Open No. 7-228268, the distance between the up edge and the down edge is evaluated based on the width of the white line that should be taken at each position in the vertical direction of the image, so that an image other than the white line is captured. Unnecessary pair edges caused by the above are removed.

[0005]

However, the white lines that define the side edges of the lane are not limited to those in which the one side of the lane is simply a continuous white line having a predetermined width. There are various embodiments, for example, a plurality of white lines arranged in the width direction of the lane. Each of these has a meaning, and provides the driver with road information.
As the vehicle is driven, the road with one white line is switched to the road with a plurality of white lines arranged, or the arrangement of a plurality of white lines is switched.

In the technique disclosed in Japanese Patent Laid-Open No. 7-228268, the unnecessary pair edge is removed without making the calculation load too high. However, even if the bright part by the white line can be properly extracted, it can be obtained by the Hough transform. The line describing the position and shape of the side edge of the lane and the line along the actual side edge of the lane may deviate from each other, and the accuracy and responsiveness were not always sufficient.

The present invention has been made in view of the above circumstances, and provides a white line recognition device capable of accurately and responsively obtaining a white line position candidate point suitable for describing the shape and position of the side edge of a lane. The purpose is to provide.

[0008]

According to a first aspect of the present invention, an image pickup means mounted on a vehicle for taking a front road surface image including a traveling lane, and the taken road surface image are laterally scanned. , The up-edge where the brightness of the image changes relatively higher than a predetermined value and the down-edge where the brightness of the image changes relatively lower than a predetermined value is detected to extract the bright part of the road surface white line, In a white line recognition device having a white line position candidate point determining means for determining a white line position candidate point representing a side edge portion of the lane at each position in the direction, the white line position candidate point determining means is used in the vertical direction of the road surface image. When only one pair edge consisting of the up edge and the down edge corresponding to the bright part is detected at the same position of, the point having a predetermined relative position preset with respect to the pair edge is the white line position. As a candidate point, when a plurality of pair edges are detected, a point having a predetermined relative position preset with respect to the plurality of pair edges is set as a white line position candidate point based on the arrangement of the plurality of pair edges. To do.

When a road portion having a plurality of white lines is continuous with a road portion having a single white line, the relative positions of the plurality of white lines and the single white line in the lane width direction are constant. There is. That is, when a single white line is formed on a road portion where a plurality of white lines are formed, the virtual formation position of the single white line is determined by the arrangement of the plurality of white lines. Since the arrangement of the plurality of white lines can be specified from the arrangement of the plurality of pair edges, in the road portion where the plurality of white lines are formed, it is obtained if the road portion is a road portion where a single white line is formed. It is possible to obtain a white line position candidate point that is equivalent to the white line position candidate point. Therefore, the line that describes the position and shape of the side edge of the lane obtained in the Hough transformation does not deviate from the line along the side edge of the actual lane.

According to the configuration of claim 2, in the configuration of the invention of claim 1, in the white line position determining device according to claim 1, the white line position candidate point determining means is the plurality of pair edges, and the horizontal direction of the road surface image. When the first pair edge and the second pair edge are arranged from the center side of, and the interval between the down edge of the first pair edge and the up edge of the second pair edge is smaller than a preset reference value,
The white line position candidate points are set to be white line position candidate points when only one second pair of edges is detected.

On the road, in addition to a road portion where a single white line continues on the shoulder side, a white line continuous with the single white line and another white line which is adjacent to and parallel to the white line on the center side of the road with respect to the white line. There is a road part formed with. In this road portion, the white lines are also relatively close to each other. In the road surface image corresponding to such a road portion, there are a first pair edge and a second pair edge from the center side in the lateral direction of the road surface image, that is, the center side of the lane, and the first pair edge down edge and the second pair edge up. The edges are arranged at relatively small intervals. Therefore, when a plurality of pair edges are arranged as described above, the white line position candidate points are set as the white line position candidate points when only one second pair edge is detected. A white line position candidate point equivalent to the white line position candidate point that would have been obtained if the road portion in which the two pair edges were detected was the road portion in which a single white line was formed is obtained.

According to a third aspect of the present invention, in the configuration of the first aspect of the invention, the white line position candidate point determining means is defined as the plurality of pair edges, from the lateral center of the road surface image to the first pair edge and the second pair edge. The paired edges of are arranged and the first
When the interval between the down edge of the pair edge and the up edge of the second pair edge is larger than a preset reference value, the white line position candidate points are the down edge of the first pair edge and the up edge of the second pair edge. It is set to be a white line position candidate point when only one pair edge is detected in the dark portion sandwiched by.

The road includes a road portion in which a single white line continues at the boundary between adjacent lanes and a road portion in which two white lines are parallel to each other. The boundary with the adjacent lane is an intermediate position between the two white lines, and the white line-not-formed band-shaped portion sandwiched between the two white lines is continuous with the single white line. Also on this road section, the white lines are relatively open. In the road surface image corresponding to such a road portion, there are a first pair edge and a second pair edge from the center side in the lateral direction of the road surface image, that is, the center side of the lane, and the first pair edge down edge and the second pair edge up. The edges are arranged at relatively large intervals. Therefore, when a plurality of pair edges are arranged as described above, the white line position candidate points are
By setting the white line position candidate point when only one pair edge is detected in the dark part sandwiched between the down edge of the first pair edge and the up edge of the second pair edge,
A white line position candidate point equivalent to the white line position candidate point that would have been obtained if the road portion in which the first and second pair edges were detected was a road portion in which a single white line was formed is obtained. .

According to a fourth aspect of the present invention, in the configuration of the first aspect of the invention, the white line position candidate point determining means is used as the plurality of pair edges from the center side in the lateral direction of the road surface image.
When the first pair edge, the second pair edge, and the third pair edge are arranged, the white line position candidate point is set as the white line position candidate point when only one second pair edge is detected. Set.

The road includes a road portion in which a single white line continues at the boundary between adjacent lanes and a road portion in which three white lines are parallel. The border between adjacent lanes is
It is in the middle position of the white line in the middle, and the white line in the middle is connected to a single white line. In the road surface image corresponding to such a road portion, the first pair edge, the second pair edge, and the third pair edge are displayed from the center side in the lateral direction of the road surface image, that is, from the center side of the lane.
The paired edges of are arranged. The white line position candidate point,
By setting the white line position candidate point when only one second pair edge corresponding to the middle white line is detected, the road portion where the first, second and third pair edges are detected is a single road part. A white line position candidate point equivalent to the white line position candidate point that would have been obtained if the road portion had a white line formed is obtained.

According to a fifth aspect of the present invention, when mounted on a vehicle,
An image pickup means for taking a front road surface image including a traveling lane, and an up edge where the brightness of the image changes relatively higher than a predetermined value by scanning the taken road surface image laterally, and the brightness of the image is relatively The white line position that determines the white line position candidate point that represents the side edge of the lane at each position in the vertical direction of the road surface image by detecting the down edge that changes lower than a predetermined level and extracting the bright part by the white line of the road surface. In the white line recognition device having a candidate point determining means, the white line position candidate point determining means, at the same position in the vertical direction of the road surface image, a pair edge consisting of the up edge and the down edge corresponding to the bright part is When one is detected, the point having a predetermined relative position with respect to the pair edge is set as a white line position candidate point, and the down edge exceeds the preset upper limit value from the up edge and the down edge is detected. If it is not output, it is considered that there is a virtual down edge at a position apart from the up edge by a predetermined reference value set in advance, and the predetermined edge with respect to the pair edge formed of the up edge and the virtual down edge. The points that take relative positions are set as white line position candidate points.

At the confluence of the two roads, an acute-angled triangular area is formed between the two roads. The white line that defines the side edge of the lane of each road is formed by edging a triangular region, and both white lines are V-shaped. And
Another white line is formed in the triangular region so as to bridge both white lines, and the plurality of white lines are formed in stripes until both roads merge. When the road surface image is scanned at the striped white line position, only the up edge is detected. The white line position candidate point is regarded as having a virtual down edge at a position apart from the up edge by a predetermined reference value set in advance, and the pair edge including the up edge and the virtual down edge is treated as described above. By using the point that takes a predetermined relative position as the white line position candidate point, in the road portion where only the up edge is detected, if the road portion is the road portion where the single white line is formed, it is obtained. It is possible to obtain a white line position candidate point that is equivalent to the white line position candidate point. Therefore, the line that describes the position and shape of the side edge of the lane obtained in the Hough transformation does not deviate from the line along the side edge of the actual lane.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the configuration of a white line recognition apparatus of the present invention which constitutes an automatic driving system on a highway, a road dedicated to automobiles, or the like. The white line recognition device has an imaging unit 1 and a white line recognition unit 2 and is mounted on a vehicle. The image pickup unit 1 is a CCD
It is a camera or a CMOS camera, and is provided with a lens on the rear-view mirror so that the front surface image of the vehicle can be taken. The white line recognition unit 2 is mainly composed of a microcomputer, and is composed of an input / output circuit, a communication circuit, and the like. The data of the image in front of the vehicle (appropriately referred to as a road surface image) obtained by the image pickup unit 1 is stored in the input buffer 2 of the white line recognition unit 2.
1, the road surface image data is converted into a format that can be captured by the white line position calculation unit (CPU) 22 in the input buffer 21, and is output to the CPU 22. The CPU 22 calculates a line (white line position) that defines the position and shape of the side edge of the lane on which the own vehicle is traveling.

The white line recognition unit 2 is a lane keep ECU 3 that automatically steers the steering of the vehicle, and a lane departure ECU that issues a warning to the driver when the vehicle is about to depart from the white line.
4 and a communication network. The white line recognition unit 2 is provided with a transmission / reception buffer 23 for transmitting / receiving data to / from the lane keep ECU 3 and the lane departure ECU 4, and the calculation result of the white line position is transferred to the transmission / reception buffer 23 so that the lane keep ECU 3 and Lane deviation ECU
4 is transmitted.

FIG. 2 shows a flow of operations executed by the CPU 22. This flow is started at a predetermined cycle by a timer interrupt with a certain offset from the vertical synchronization signal. First, in step S11, a road surface image is captured so that the brightness of each pixel can be referred to.

In step S12, white line position candidate points are determined. The white line position candidate point is determined by first scanning in the road width direction, that is, the lateral direction of the road surface image, and extracting the bright portion. As shown in FIG. 3, at the side edge of the white line, the brightness rises or falls in a stepwise manner.
If the brightness changes in the + direction (up edge), there is a possibility of the start of the light part, that is, one side edge in the width direction of the white line, and then if the brightness changes in the-direction (down edge), There is a possibility of the end, that is, the other side edge portion in the width direction of the white line. In scanning, a pair edge composed of an up edge and a down edge adjacent to each other is detected. The scanning is performed 60 times as shown in FIG.
The numbers (-) in the figure indicate the scanning order, and scanning is performed at 30 vertical positions. In the road surface image, a white line L01 that defines the left side edge of the lane and a white line L02 that defines the right side edge of the lane are reflected in a V shape. In the illustrated example, the white line L01 on the left side is the white line on the shoulder side and the white line L on the right side.
02 indicates a white line which is a boundary with the adjacent lane.

In the first scanning, scanning is performed from the lateral center of the road surface image to the right, and if the brightness is higher than the preset reference value than the adjacent pixel, it is an up edge, and if it is low,
Down edge. The lateral center of the road surface image at which scanning starts is normally the center of the lane. Then, based on whether or not the interval between the up edge and the down edge forming the pair edge (hereinafter, appropriately referred to as the width of the pair edge) is within a predetermined range, it is possible to obtain only the pair edge having a high probability of being the bright part by the white line. it can. Here, the above-mentioned predetermined range for screening whether or not it is a bright part by a white line is variable according to the position of the road surface image in the vertical direction (hence, depending on how many times the scanning is performed), and the above-mentioned JP-A-7-228268. As described in (1), a larger value is given to the lower side of the road surface image in which the white line near the vehicle is widened. Thereby, regardless of the position in the vertical direction, it is possible to obtain only the pair edges in which the width that can be regarded as a white line in the bird's-eye view conversion falls within the width lower limit threshold value or more. When the scanning reaches the rightmost pixel of the road surface image, the first scanning ends. In the scanning, as will be described later in detail, the white line position candidate point which is the side edge position of the lane on which the own vehicle travels is determined based on the data of the pair edge which is the bright part with the white line and which is highly probable.

Similarly, in the second time, the vertical position is the same, and scanning is performed from the center of the image in the horizontal direction to the left, and if the brightness is higher than that of the adjacent image, the edge is up edge, and if the brightness is lower than the adjacent image, the edge is down edge. When the scanning reaches the leftmost pixel of the road surface image, the second scanning ends. White line position candidate points are also determined in the scan.

Next, the coordinates are shifted downward in the vertical direction, and the third
The fourth and fourth scans are performed. The third scan is the first
Similar to the first time, the image is scanned from the center in the horizontal direction to the right to detect the up edge and the down edge. In the fourth scanning, similarly to the second scanning, the scanning is performed from the center of the image in the horizontal direction to the left. In this way, the up-edge and the down-edge are detected by alternately scanning left and right in the horizontal direction at 30 points in the vertical direction. As a result, the data of only the pair edges, which are the bright parts due to the white lines and are highly probable, are collected in the entire road surface image, and the white line position candidate points are determined in each scan.

In scanning at each vertical position, as shown in FIG. 5, after the up edge E11, the down edge E12 paired with the up edge E11 comes (pair edge E1 detection), and a preset threshold value is set from the down edge E12. If an up edge is not detected beyond the range, the white line L is detected in the scanning range.
It is determined that "1" is a line with 1 being only 1. In this case, the intermediate position between the up edge and the down edge is the white line position candidate point.

Further, in the scanning of each vertical position, FIG.
As shown in (1), after the up edge E211, a down edge E212 which is paired with the up edge E211 comes (first pair edge E2
21 detection), and further, after the up edge E221, a down edge E222 paired with the up edge E221 comes (second pair edge E22 detection), the up edge exceeds the threshold value of the interval between the down edge E222 and the pair edge, If not detected, the white lines L21 and L22 in the scanning range.
Is determined to be two “two-line”.

Further, FIG. 7 shows another mode in which two white lines are provided. The up-edge E is generated during scanning at each vertical position.
After 311, a down edge E312 paired with the down edge E312 comes (first pair edge E31 detection), and further, after an up edge E321, a down edge E32 paired therewith.
2 (the second pair edge E32 is detected), if the up edge is not detected from the down edge E322 beyond the threshold value, the white line L3 is detected in the scanning range.
It is determined that 1 and L32 are two "two lines".

Here, the first pair edge E21 (E3
1) the down edge E212 (E312) and the second pair edge E22 (E32) the up edge E221 (E3).
21) is smaller than the threshold value,
It can be determined that the arrangement of white lines is the arrangement shown in FIG. This arrangement is an arrangement that appears at the boundary with the road shoulder, and it can be determined that the road shoulder side is a continuous white line L21 and the center side of the road is a dashed white line L22. In this arrangement, the roadside white line L21 is connected to the "one-line" white line as shown in FIG. Therefore, in this case, the intermediate position between the up edge E221 and the down edge E222 of the second pair edge E22 is set as the white line position candidate point (voting).

Further, in the case of "two lines", the down edge E212 (E31) of the first pair edge E21 (E31).
When the interval between 2) and the up edge E221 (E321) of the second pair edge E22 (E32) is larger than the threshold value, it can be determined that the array of white lines is the array shown in FIG. This sequence is a sequence that appears at the boundary with the adjacent lane, and the boundary with the adjacent lane is
It is an intermediate position between the white lines L31 and L32 of the book. In this arrangement, the strip-shaped dark portion sandwiched between the down edge E312 of the first pair edge E31 and the up edge E321 of the second pair edge E32 is continuous with the “single line” white line as shown in FIG. Therefore, in this case, it is considered that there is a white line in the dark portion, and the down edge E312 of the first pair edge E31 and the up edge E of the second pair edge E32.
An intermediate position with 321 is set as a white line position candidate point (voting). In the example shown in the figure, two parallel white lines L31 and L32 and one parallel white line L33 appear alternately, but the present invention is not limited to this.

Alternatively, an intermediate position between the up edge E311 of the first pair edge E31 and the down edge E322 of the second pair edge E32 is set as a white line position candidate point.

The threshold value of the interval is variable according to the vertical position of the road image in the same manner as the lower limit threshold value of the width so that the case of FIG. 6 and the case of FIG. 7 can be distinguished. It is set based on the white line specifications. For example, 30 in bird's eye view conversion
cm.

Further, in the scanning of each vertical position, FIG.
As shown in FIG. 5, after the up edge E411, the down edge E412 which is paired with the up edge E411 comes (first pair edge E
41 detection), further, after the up edge E421, a down edge E422 paired with this comes (second pair edge E42 detection), and further, after the up edge E431, a down edge E432 paired with this comes. Third
Detection of the pair edge E43 of), in the scanning range,
White lines L41, L42, and L43 are determined to be three "three lines". This sequence is a sequence that appears at the boundary with the adjacent lane, and the boundary with the adjacent lane is the second white line L42 in the middle.
Is an intermediate position. In this arrangement, the second pair of edges E
42 is connected to the "one-line" white line as shown in FIG. Here, the three white lines L41 to L43 have the same width and are equivalent, and are arranged at equal intervals. Therefore, the first pair of edges E4
An intermediate position between the up edge E411 of 1 and the down edge E432 of the third pair edge E43 is set as a white line position candidate point (voting).

Alternatively, the intermediate position of the second pair edge E42 is set as the white line position candidate point.

Further, in the scanning of each vertical position, FIG.
As shown in, after the up edge E511 is detected,
When the down edge is not detected by exceeding the preset threshold value, it is determined that the side edge portion of the lane is defined by the white painting patterns L51, L52, L53 different from the normal white line in the scanning range. To do. Here, the threshold value is set to an upper limit threshold value of the width of the white lines that can be regarded as the white lines L1, L21, etc. along the side edge of the lane. The width upper limit threshold is, of course, also variable according to the position of the road surface image in the vertical direction, and is, for example, 40 cm in bird's eye view conversion.

Such a situation appears, for example, at the confluence of two roads. At the junction of the two roads, an acute triangular area A is sandwiched between the two roads. The white-painted patterns L51 to define the side edges of the lanes of the two roads
In L53, a white line L51 defining the side edge of the first road and a white line L52 defining the side edge of the second road are triangular areas A.
Is formed by edging, and both white lines L51 and L52 form a V shape. Further, another white line L53 is formed in the triangular region A so as to bridge both white lines L51 and L52, and a plurality of white lines L53 are formed in stripes until both roads merge. When the road surface image is scanned at the position of the striped white line L53, only the up edge E511 is detected.

In this case, the white line position candidate point is set at a position of a predetermined distance set in advance from the up edge E511 (voting). Here, the predetermined distance is the white lines L1, L
Set it to 1/2 of the standard width such as 21. That is, the white line position candidate point is determined by assuming that there is a virtual down edge at a position separated from the up edge E511 by the standard width. Of course, the standard width is also variable according to the vertical position of the road surface image, for example, 20 cm in bird's eye view conversion.

In the subsequent step S13, the white line position candidate points in the road surface image are voted and Hough transformed to determine the temporary white line position. The Hough transform is a two-dimensional space specified by two parameters that specify a straight line that passes through the voted white line position candidate points. What happens frequently when all the white line position candidate points in the road image are voted. Do by asking. This straight line is a temporary line that describes the position and shape of the side edge of the lane.

In step S12, even if the road portion appearing in the road surface image does not have a simple "single line", the road portion can be obtained if the road portion has a single white line. Since it is possible to obtain a white line position candidate point equivalent to the likely white line position candidate point, step S
The straight line obtained in 13 shows the position and direction of the side edge of the lane well just before the vehicle. The point on this straight line is the position of the provisional white line.

In a succeeding step S14, a pair edge is searched for by scanning left and right from the temporary white line position, and if a pair edge exists, it is stored. The pair edges also include the pair edges existing on the temporary white line position.

In step S15, points representative of the side edges of the lane are obtained based on the searched pair edges as in the white line position candidate points, and a least squares approximation is performed for these point groups, and this curve is It is a line that describes the position and shape of the side edge. The point on this curve is the final white line position.

The information about the position of the white line is transmitted to the lane keep ECU 3 via the transmission / reception buffer 23 and reflected in the control amount of the automatic steering. Also, lane departure warning EC
It is sent to U4 and is used to judge whether or not the own vehicle has left the lane.

As described above, according to the present embodiment, if the road portion as shown in FIGS. 6 to 9 is a road portion on which a single white line is formed, it is obtained as a white line position candidate point. Since a white line position candidate point equivalent to the likely white line position candidate point is obtained, the line describing the position and shape of the side edge of the lane and the line along the actual side edge of the lane deviate from each other. The position of the white line can be accurately obtained with good responsiveness.

Further, the arrangement of a plurality of white lines is shown in FIGS.
However, the present invention is not limited to this, and if there is one used as a road sign, when a plurality of pair edges corresponding to the array of the plurality of white lines are detected, On the other hand, a point having a predetermined relative position set in advance is a white line position candidate point. As a result, a white line position candidate point equivalent to the white line position candidate point that would have been obtained if the road portion in which a plurality of pair edges were detected was the road portion in which a single white line was formed is obtained.

In the present embodiment, the position of the white line is represented by the intermediate position of the white line in the lane width direction, but the position is not limited to the intermediate position and is arbitrary. This is because, for example, in the control of automatic traveling or the determination of whether to issue a lane departure warning, which range in the width direction of the lane the vehicle should travel can be appropriately set.

Further, although the image pickup unit for taking a road surface image in front of the vehicle is configured to output a digital signal and receives the image signal at the input buffer, the image pickup unit may also be used as an image pickup unit for outputting the image signal as an analog signal. Well, in this case,
As shown in, the image signal from the image pickup unit 1A is converted into a digital signal by the analog-digital converter 24 and output to the input buffer 21.

Further, as shown in FIG. 11, the digital image signal from the image pickup section 1 and the analog-digital converter 24 is stored in the image memory 25 which temporarily stores the brightness of each pixel of the road surface image. You may make it take in in CPU22 suitably. Further, instead of a configuration having an external memory such as the input buffer 21 and the image memory 25, a digital image signal may be directly input to the CPU in view of the recent increase in the speed of the CPU.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a white line recognition device of the present invention.

FIG. 2 is a flowchart illustrating a white line position calculation processing procedure in the white line recognition apparatus.

FIG. 3 is a first diagram illustrating a procedure of extracting a bright portion by a white line from a road surface image in the white line recognition device.

FIG. 4 is a second diagram illustrating a procedure of extracting a bright portion by a white line from a road surface image in the white line recognition device.

FIG. 5 is a first diagram showing types of white lines formed on a road surface.

FIG. 6 is a second diagram showing types of white lines formed on a road surface.

FIG. 7 is a third diagram showing types of white lines formed on a road surface.

FIG. 8 is a fourth diagram showing types of white lines formed on a road surface.

FIG. 9 is a fifth diagram showing types of white lines formed on a road surface.

FIG. 10 is a first diagram showing a modified example of the white line recognition device.

FIG. 11 is a second diagram showing a modified example of the white line recognition device.

[Explanation of symbols]

1, 1A Image pickup unit (image pickup unit) 2 White line recognition unit 21 Input buffer 22 White line position calculation unit (white line position candidate point determination unit) 23 Transmission / reception buffer 3 Lane keep ECU 4 Lane deviation ECU L01, L02, L1, L21, L22, L31, L3
2, L33, L41, L42, L43, L51, L5
2, L53 white line E1, E21, E22, E31, E32, E41, E4
2, E43 Pair edges E11, E211, E221, E311, E321, E
411, E421, E431, E511 Up edges E12, E212, E222, E312, E322, E
412, E422, E432 Down edge

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Katsuyuki Imanishi             14 Iwatani Shimohakaku-cho, Nishio-shi, Aichi Stock Association             Company Japan Auto Parts Research Institute F term (reference) 5B057 AA16 CH01 CH11 DA15 DC16                       DC22                 5H180 AA01 CC04 FF27 FF32 LL02                       LL04 LL07                 5L096 BA04 CA02 DA02 FA06 FA14                       FA69

Claims (5)

[Claims] 1. An image pickup means mounted on a vehicle for taking a front road surface image including a traveling lane, and a taken road surface image are laterally scanned to change the brightness of the image relatively higher than a predetermined level. The up edge and the down edge where the brightness of the image changes relatively lower than a predetermined level are detected to extract the bright part by the white line of the road surface, and the side edge part of the lane is detected at each position in the vertical direction of the road surface image. In a white line recognition device having a white line position candidate point determining means for determining a representative white line position candidate point, the white line position candidate point determining means, at the same position in the vertical direction of the road surface image, corresponding to the bright portion. When only one pair edge consisting of the up edge and the down edge is detected, a point having a predetermined relative position with respect to the pair edge is set as a white line position candidate point, and a plurality of pair edges are detected. When the can, based on the sequence of Peaejji the plurality of white line recognition apparatus being characterized in that the point of taking the predetermined relative position previously set for the plurality of Peaejji set to the white line position candidate point. 2. The white line recognition device according to claim 1,
As the plurality of pair edges, the white line position candidate point determining means has a first pair edge and a second pair edge arranged from the lateral center of the road surface image, and includes a first pair edge down edge and a second pair edge. A white line recognition device set so that the white line position candidate point is a white line position candidate point when only one second pair edge is detected when the distance from the up edge is smaller than a preset reference value. . 3. The white line recognizing device according to claim 1,
As the plurality of pair edges, the white line position candidate point determining means has a first pair edge and a second pair edge arranged from the lateral center of the road surface image, and includes a first pair edge down edge and a second pair edge. When the distance from the up edge is larger than a preset reference value, the white line position candidate point has only one pair edge in the dark part sandwiched by the down edge of the first pair edge and the up edge of the second pair edge. A white line recognition device set to be a white line position candidate point when it is detected. 4. The white line recognizing device according to claim 1,
When the first pair edge, the second pair edge, and the third pair edge are arranged from the lateral center of the road surface image as the plurality of pair edges, the white line position candidate point determining means determines the white line position candidates. A white line recognition device in which a point is set as a white line position candidate point when only one second pair edge is detected. 5. An image pickup means mounted on a vehicle for taking a front road surface image including a traveling lane, and the taken road surface image are laterally scanned so that the brightness of the image changes relatively higher than a predetermined level. The up edge and the down edge where the brightness of the image changes relatively lower than a predetermined level are detected to extract the bright part by the white line of the road surface, and the side edge part of the lane is detected at each position in the vertical direction of the road surface image. In a white line recognition device having a white line position candidate point determining means for determining a representative white line position candidate point, the white line position candidate point determining means, at the same position in the vertical direction of the road surface image, corresponding to the bright portion. When one pair edge consisting of an up edge and the down edge is detected, a point having a predetermined relative position set in advance with respect to the pair edge is set as a white line position candidate point and set in advance from the up edge. When the down edge is not detected beyond the upper limit value, it is considered that there is a virtual down edge at a position apart from the up edge by a predetermined reference value, and the up edge and the virtual down edge are The white line recognition device is characterized in that the point having the predetermined relative position with respect to the pair edge consisting of is set as a white line position candidate point.